By Stephen Gibbs
BBC News, Havana
Cuban authorities have released some of the group of 20 dissidents detained shortly before a planned protest in Havana on Friday.
Martha Beatriz Roque was among those freed
According to the independent Cuban Commission for Human Rights, at least five people have been released.
Among those who have been allowed home after being questioned overnight, is a leading dissident economist.
Martha Beatriz Roque, jailed twice over the last decade, seems to have been given a clear warning by authorities.
She and the 20 or so other dissidents rounded up on Friday had been intending to take part in a protest outside the French embassy in Havana.
They are calling for Europe to do more to seek the release of Cuba's political prisoners.
The same group of dissidents organised a rare public meeting in May, in which about 200 delegates demanded radical change in Cuba's political and economic systems.
President Fidel Castro usually portrays Cuba's dissident movement as both insignificant and in the pay of the US.
But this crackdown on the opposition comes at a time when there have been some signs of general discontent in the country.
Extended power cuts at the height of summer, combined with the after-effects of Hurricane Dennis have prompted occasional, isolated protests.